Jordan Journal of Civil Engineering

Prediction of Side Weir Discharge Coefficient by Genetic Programming Technique


Abbas Parsaie; Amir Hamzeh Haghiabi;


Side weir has many possible uses in hydraulic engineering and has also been investigated as an important structure in hydrosystems. In this paper, the genetic programing technique was used to predict side weir discharge coefficient. The main parameters which are efficacious in the side weir discharge coefficient are: Froude number (Fr), ratio of side weir height to total upstream head 􁈺 􀯉 􀯛􀰭 ), ratio of side weir length to total upstream head 􁈺 􀯅 􀯛􀰭 ) and ratio of side weir length to channel width (􀯅 􀯕). Principal component analysis indicates that the most important parameters are: Fr1 and 􀯉 􀯛􀰭 . The results show that the most accurate empirical formula is the Emiroglu formula with error indices (R2 = 0.64 and RSME=0.1). The performance of GP was compared to the empirical formulae proposed to calculate Cdsw. The results of the GP model indicate that the accuracy of the GP model with error indices (R2 = 0.95 and RSME=0.09) is suitable. At the end, a formula is proposed to calculate Cdsw based on the GP approach.


Hydraulic structures,Weir, GP, Discharge coefficient, Principal component analysis